CVE-2026-23818: HPE Aruba 5G Core Open Redirect Vulnerability

CVE-2026-23818 Overview

A vulnerability has been identified in the graphical user interface (GUI) of HPE Aruba Networking Private 5G Core On-Prem that could allow an attacker to abuse an open redirect vulnerability in the login flow using a crafted URL. Successful exploitation may redirect an authenticated user to an attacker-controlled server hosting a spoofed login page prompting the unsuspecting victim to give away their credentials, which could then be captured by the attacker, before being redirected back to the legitimate login page.

Critical Impact

Attackers can exploit this open redirect vulnerability to steal user credentials through credential harvesting attacks, potentially compromising 5G network infrastructure management access.

Affected Products

• HPE Aruba Networking Private 5G Core On-Prem GUI

Discovery Timeline

• 2026-04-07 - CVE CVE-2026-23818 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-23818

Vulnerability Analysis

This vulnerability is classified as CWE-601 (URL Redirection to Untrusted Site, also known as Open Redirect). The flaw exists within the authentication flow of the HPE Aruba Networking Private 5G Core On-Prem web interface. When users attempt to log in, the application fails to properly validate redirect URLs, allowing attackers to craft malicious links that redirect authenticated users to external, attacker-controlled sites.

The attack requires user interaction—a victim must click on a crafted URL. Once clicked, the user is seamlessly redirected to a malicious server that presents a convincing replica of the legitimate login page. After the victim enters their credentials on this fake page, the attacker captures the authentication data before redirecting the user back to the real login page, making the attack difficult to detect.

Root Cause

The root cause of this vulnerability is improper input validation of URL redirect parameters within the login flow of the HPE Aruba Networking Private 5G Core On-Prem GUI. The application does not adequately verify that redirect destinations are within the application's trusted domain, enabling attackers to specify arbitrary external URLs as redirect targets.

Attack Vector

The attack vector is network-based, requiring no prior privileges but requiring user interaction. An attacker would typically:

1. Craft a malicious URL targeting the vulnerable application's login endpoint
2. Include a redirect parameter pointing to an attacker-controlled server
3. Distribute the malicious link via phishing emails, social engineering, or other means
4. Host a spoofed login page on the attacker-controlled server to harvest credentials
5. Capture the victim's credentials when they enter them on the fake login page
6. Redirect the victim back to the legitimate login page to avoid suspicion

Since the initial URL appears to be from the legitimate HPE Aruba Networking domain, victims are more likely to trust the link and enter their credentials, making this attack particularly effective in targeted phishing campaigns against 5G network administrators.

Detection Methods for CVE-2026-23818

Indicators of Compromise

• Unusual login page requests containing redirect parameters pointing to external domains
• HTTP referer headers showing traffic originating from unexpected external sites
• User reports of being redirected to unfamiliar login pages before accessing the legitimate interface
• Failed login attempts following successful credential entries, indicating credential harvesting

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests with external redirect parameters
• Monitor authentication logs for patterns indicating credential harvesting, such as immediate re-authentication attempts
• Deploy URL filtering solutions to identify and flag suspicious redirect patterns in network traffic
• Configure security monitoring to alert on login attempts originating from unexpected geographic locations

Monitoring Recommendations

• Enable detailed logging on the HPE Aruba Networking Private 5G Core On-Prem GUI to capture all authentication-related events
• Monitor for spikes in login failures that may indicate credential stuffing using harvested credentials
• Implement user behavior analytics to detect anomalous access patterns following potential credential theft
• Review referrer logs regularly to identify any redirect abuse attempts

How to Mitigate CVE-2026-23818

Immediate Actions Required

• Review the HPE Support Document for official vendor guidance and patches
• Educate users about the risks of clicking on links in unsolicited emails or messages
• Implement multi-factor authentication (MFA) to reduce the impact of credential theft
• Consider restricting access to the management GUI to trusted IP ranges or VPN connections only

Patch Information

HPE has published a security advisory addressing this vulnerability. Administrators should consult the HPE Support Document for specific patch information and remediation guidance. Apply all available security updates to the HPE Aruba Networking Private 5G Core On-Prem platform as soon as possible.

Workarounds

• Implement network-level controls to restrict management interface access to trusted internal networks
• Deploy a reverse proxy with URL validation capabilities to filter malicious redirect attempts before they reach the application
• Train administrators to always verify the URL in their browser's address bar before entering credentials
• Consider implementing browser-based security controls or extensions that warn users about potential redirect attacks